Étude de la réaction 11B + p → 3α À Ep = 7.18 MeV

doi:10.1016/0375-9474(67)90491-5

Nuclear Physics A

Volume 97, Issue 2, 25 April 1967, Pages 321-336

https://doi.org/10.1016/0375-9474(67)90491-5 Get rights and content

Abstract

Several continuous α-particle spectra were measured from the sequential reaction $^{11} B + p →^{12} C^{∗} → α +^{8} Be^{∗} → 3α at E_{p} = 7.18 MeV$ . The measured spectra are in agreement with a theoretical expression derived on simple assumptions except when all the energy available is taken up by 2 α-particles. This type of event is forbidden.

Références (16)

A.E. Pitts
Nuclear Physics
(1963)
J.D. Bronson
Nuclear Physics
(1965)
N. MacDonald
Phys. Lett.
(1965)
T. Lauritsen et al.
Nuclear Physics
(1966)
L. Marquez
thèse
(1966)
E.H. Beckner et al.
Phys. Rev.
(1961)
J.P. Longequeue
Compt. Rend.
(1966)
R. Bilwes et al.

There are more references available in the full text version of this article.

Cited by (9)

About the influence of space-time separations between sources of α-particle emission in the reaction p+11B→3α on interference phenomena in their spectra
1991, Physics Letters B
Angular correlation and reaction mechanism for 11B(p,α)8Be<inf>2.9</inf>(α)4He with E<inf>p</inf> < 1.4 MeV
1972, Nuclear Physics, Section A
The α-α angular correlation from the sequential decay of the ¹¹B(p,α)⁸Be_2.9(α)⁴He reaction indicates that this reaction proceeds by compound-nucleus formation of ¹²C states of E_x, J^π = 16.11(2⁺), 16.58(2⁻ and 17.23(1⁻). For E_p = 0.163, 0.675, 1.00 and 1.39 MeV, and for a first-emitted α-partiele angle of 90°, kinematically complete experiments provide observed symmetry axes for the ⁸Be_2.9 break-up distribution in its own c.m. system. The axis for each correlation function, when compared to the momentum transfer and recoil directions associated with various possible mechanisms, indicates that compound-nucleus formation is the predominating mechanism at each beam energy. The correlation functions at the resonant proton energies of 0.163, 0.675 and 1.39 MeV are consistent with the capture states having J^π = 2⁺, 2⁻ and 1⁻, respectively.
Effets des spin et parité 3- de 12C (18.36 MeV) sur la répartition des énergies dans l'état final de la réaction 11B(p, 3α)
1972, Nuclear Physics, Section A
Decay of 12C via the 11B(p, 2α)α reaction
1972, Nuclear Physics, Section A
The ¹¹B(p, 2α)α reaction has been studied in a kinematically complete experiment over a wide range of angles at bombarding energies corresponding to resonances in ¹²C at E_x = 17.23 MeV, 17.77 MeV and 18.36 MeV. The coincidence spectra exhibit interference effects which can be reproduced theoretically if the identity of the three final-state particles is properly taken into account. A strong dependence of the cross section on the channel spin s and the angular momentum L in the 2α subsystem is demonstrated. Although no effort was made to produce best fits to the data, satisfactory overall agreement between theory and experiment could be obtained. The results of the calculations support the assignment I^π = 3⁻ for the resonance in ¹²C at E_x = 18.36 MeV.
Interprétation des résultats expérimentaux de la réaction 11B(p, 3α) entre 0.68 ET 2 MeV
1970, Nuclear Physics, Section A
The reaction amplitude ℸ of the ¹¹B (p, 3α) reaction is written as $ℸ = τ + TG_{o} τ$ , where τ corresponds to the production of three uncorrelated α-particles by the reaction ¹¹B + p, and T is the Faddeev operator in the three-body channel. The numerical calculation is made in the final state interaction approximation, i.e. T ≈ t, where t is the two-body αα amplitude, given by the well-known phase-shifts δ₀ and δ₂. We write the matrix-element 〈f¦τ¦i〉 as a Breit-Wigner formula, and after an angular decomposition of the total amplitude ℸ, we obtain a good description of the Dalitz-plot for the J^π = 2⁻, 1⁻ and 0⁺ levels of ¹²C.
Investigation of the reaction mechanisms in the11B+p → 3α Reaction at 20 MeV
1981, Il Nuovo Cimento A

View all citing articles on Scopus

View full text

Article preview

Nuclear Physics A

Abstract

Références (16)

Nuclear Physics

Nuclear Physics

Phys. Lett.

Nuclear Physics

thèse

Phys. Rev.

Compt. Rend.

Cited by (9)

About the influence of space-time separations between sources of α-particle emission in the reaction p+<sup>11</sup>B→3α on interference phenomena in their spectra

Angular correlation and reaction mechanism for <sup>11</sup>B(p,α)<sup>8</sup>Be<inf>2.9</inf>(α)<sup>4</sup>He with E<inf>p</inf> < 1.4 MeV

Effets des spin et parité 3<sup>-</sup> de <sup>12</sup>C (18.36 MeV) sur la répartition des énergies dans l'état final de la réaction <sup>11</sup>B(p, 3α)

Decay of <sup>12</sup>C via the <sup>11</sup>B(p, 2α)α reaction

Interprétation des résultats expérimentaux de la réaction <sup>11</sup>B(p, 3α) entre 0.68 ET 2 MeV

Investigation of the reaction mechanisms in the<sup>11</sup>B+p → 3α Reaction at 20 MeV